Synchronous motor driven chime movement for clocks



F. HECKERT Sept. 17, 1935.

SYNCHRONOUS MOTOR DRIVEN CHIME MOVEMENT FOR CLOCKS Filed Jan. 6, 1931 2 Sheets-Sheet 1 ATTORNEY Patented Sept. 17, 1935 q UNITED STATES SYNCHRONOUS MOTOR DRIVEN CHIME MOVEMENT FOR CLOCKS Fritz Heckert,

Sehwenningen-on-the -Neckar,

Germany, assignor to Kienzle Uhrenfabriken A. G., Schwenningen-on-the-Neckar, Germany, a corporationof Germany Applicalicn January 6, 1931, Serial No. 506,847

In Germany September 27, 1930 8 Claims.

This invention relates to an electrically operated striking or chime clock which is driven by a continuously rotating motor, in the present instance, preferably an A. C. synchronous motor.

5 In clocks of this type it is customary to have the entire driven time gear train, or at least its driving means (spring or Weight) continuously and permanently associated in driving relation with the driving motor by means of a gear drive. At the same time, however, during the striking operation, the normally non-connected strikingtrains must be mechanically coupled with said driving motor. For this purpose, in past practice, it has been customary to utilize shiftable, normally non-operative jaw couplings or clutches between the driving motor. and the train and which are adapted to be engaged with and disengaged from the continuously rotating clock driving mechanism. As a modification, it has also been customary to arrange the first gear wheel of the arrested strike driving gear train as a sort of movably engageable or disengageable clutch, such as an axially displaceable gear adapted to be meshed or unmeshed with the contin- 5 uously rotating members of the driving power by a suitable control means.

These previous arrangements, however, have the disadvantage that the above noted meshing or unmeshing or coupling actions cannot be set to coincide exactly with correct time periods, and

a perceptible time period loss occurs in the-striking action, the result being that the striking will be inaccurate.

In addition, such an arrangement when apa plied to household clocks has the particularly important disadvantage that the strike clutching or engaging and disengaging movements create an undesirable clashing noise,

In the present invention, in. order to obviate these disadvantages, the driving wheels of the otherwise commonly arrested striking trains are so constructed as to be kept constantly in motion and remain continuously and positively coupled with the constantly driven time trains by means of suitable, intermediate constantly coupled planetary gear trains. The driving power is then transmitted by time gearing, in the well known manner, to the corresponding strike train by locking one of the rotating parts of the inter- 30 mediate train for a given period. This locking is preferably performed by the striking ratchet mechanism or the dial hand motion operation of the constantly running time train.

Another advantage is that if the chime'striking means should be out of step or time, the strike regulator will eventually be automatically reset to cause the chimes to be struck in proper sequence and time.

These and other capabilities will-be appre- 30 hended as the herein description proceeds, and it.

is obvious that modifications may be made in the device without avoiding the spirit. hereof or the scope of the appended claims.

I The accompanying drawings illustrate an embodiment of the invention as applied to a strik- 5 ing train clock driven by a synchronous electric motor, wherein Fig. 1 is a front view of a time train, with part of the front plate of the movement being removed; i

Fig. 2 illustrates a front View of the striking lever mechanism, the front movement plate being partially removed;

Fig. 3 depicts the front plate with details of the locking lever and action during the locking operation;

Fig, 4 is a fragmentary section, enlarged, taken 'on the line 4-4 of Fig. 1, looking in the direction of the arrow, showing the hour strike gear coupling;

Fig. 5 is a fragmentary section, enlarged, taken on the line 55 of Fig. 1, looking in the direction of the arrow, showing the quarter strike gear coupling; I

Fig. 6 shows the strike regulating means, removed from position, andillustrates the action thereof on the quarter-past stroke when in correct position to strike the chimes.

Fig. 7 shows the same means but in incorrect position or partially out of time, when the chimes will not sound; and

Fig. 8 discloses the action of the quarter hour strike regulator with the cam out of time, but on the hour, at which setting the chimes will sound, and the cam permitted to run to reset to resume correct striking position,

Fig. 9 is a sectional view taken on line 9-9,, Fig. 1, looking in the direction of the arrows; and Fig. 10 is a sectional view taken on line Ill-40, Fig. 1, looking also in the direction of the arrows.

In Fig. 1, I indicates a continuously rotating synchronous motor of well known type having a driving pinion I, used for driving the clockand which, by means of intermediate gears 2, 3

' meshed to rotor pinion I, as shown, is connected with the planetary train 4, 5, 6, Figs. 3 and 4, of the hour striking mechanism generally denoted by l. As shown in Fig. 9, the gear 4 is rigidly attached to the accompanying bevel gear on the shaft 22, and on the hub of this bevel gear, as shown, is rigidly mounted a pinion 4'. This pinion is in mesh with the gear 8, rigid with which is a pinion 8', and the last mentioned pinion meshes with a gear l4; The gear M has on the opposite end of its shaft, as shown, a pinion 9, which meshes with a gear in, and on this latter gear is a pinion In which meshes in driving relation with a gear ll, Fig. 10. Rigid with the shaft of the gear H, as shown, is a pinion ll, 60

and this pinion meshes with a gear i2, towhich is affixed a dial hand shaft l3.

The second gear and pinion train 8, 9 branches off in front of'the intermediate train 2, 3 and is adapted, by means of the gear and pinion wheels in, II to transmit power to drive the time train (the latter being provided with the dial hand shaft l3) and also by means of a gear 14 to transmit motion to a second planetary gear train l6, i1, (8 operating the quarter hour striking mechanism l9, Figs. 4 and 5.

It is obvious that as the motor I rotates, it will positively drive the driving gear and pinions 3, 4 and II), II and i2 of the time train, and also the planetary striking trains 1 and i! of both thehour and quarter hour striking mechanisms. The operating means in the present instance comprises a synchronous motor and hence requires no driving power, per se, such-as a spring or weight; and thus all of the time train up to and including the dial hand wheel I2 is positivelv coupled with the driving motor and hence runs continuously.

As long as the running clock is not striking, both the hour and the quarter hour strike mechanism trains are at rest. This is accomplished by the use of the planetary gear trains 4, 5, 8 or l5, i1, i3, Figs. 4 and 5. Each train consists of two sun gears 4 and 5, and i5 and i8 and planet gears 5 or l1. The latter gears are respectively rotatably mounted on vertical shafts 20 and 2| carried in turn by shaft 22 and 23. The two sun gears 4, 6 and i6, i8 are each rotatably journaled on shafts 22 and 23.

The driving sun gears 4 and I6 are in mesh with the continuously rotating gears 3 and I4 and hence rotate continuously. The driving sun gears 6 and i8 each have locking plates 24 and 25 and are adapted to be stopped thereby as indicated in Figs. 4 and 5. This construction causes the planet gears 5 and I1 to move around the stationary sun gears 5 and I3 and thus carry the shafts 22 and 23 along. Since each of these shafts is connected with the rest of its gear train, the result is that when the sun gears 5 and i! are locked, their gear trains will be set in motion.

The shaft 22 of the planetary gear train 4, 5, 3 of the hour striking mechanism 1 carries on its free end Figs. 3 and 4, and in front of the front movement plate A, the actuator 28 of the well known snail arrangement 21, 23, 28. The rear end of the shaft 22 carries the striking cam 30 of the hour hammer operator 3|.

A locking member is provided for the planetary gear train 4 ,5, 6, of the hour striking mechanism 1 in the form of a pawl 33, (Fig. 2) pivoted on shaft 32, and which is retracted by spring 34 and prevented from dropping into the locking ratchet teeth on wheel 24.

The other end 36 of said pawl 32 is bent at right angles and operates in the path of a pivoted angular locking lever 33 loosely pivoted on the pin 31 and which lever has an extension 30 provided with a resiliently pivoted blocking ratchet abutment 40.

The other extension 4| of the lever 33 is biased by spring 42 to cause its angularly turned end 44 to bear constantly upon the periphery of a disk 43, having a notched portion i 44. In addition. a carrier stud or pin 45 on the locking lever arm 4i rests upon the well known drop-in lever 21 of the rack arrangement 28, 23 so that the locking lever 3| is really supported by the I Figs. 2 and 5, there is fastened an actuating disc 50 provided with four notch portions of progressively increasing distances apart and of the well known type.

A jumper disc 5| is provided to cooperate with said locking disc 50, the two being resilientlyl connected together in the well known manner. The shaft 23 in addition carries (in front of the front movement plate A) an hour release cam 52 while the rear end of the shaft 23 carries the driving wheel 53' for operating the striking arrang'ement 54 and the, hammers 55, as in Figs. 1 and 5.

A locking pawl 51, which is pivoted at 58 (Fig. 2) serves as a locking member for the intermediate train i6, l1, l8, said locking pawl being prevented from engaging its end 59 into notches of the locking disk 25 by a spring 53. The other bent end 60 of said pawl protrudes into the path of arm SI of a three armed locking lever 52, which is rotatably journaled on 62. The arm Ii also carries at this point a unilaterally blocking ratchet abutment 85. The second arm 64 of I the locking lever 63 rests against the actuating at every strike release period by the release lever 68, B8 and release snail 10, as in Figs. 6, 7, 8.

The train of the quarter striking mechanism is controlled to operate in the following manner: Before each strike release period the release snail 10 lifts the locking lever 63 through the intermedinry of the release lever 83, 63 and the transmitting lever 31 until the releaselever 54 has reached the highest point of the corresponding extension or tooth of the release snail 10, Figs. 6. 7 and 8. During this rotation of the locking lever 53 the unilaterally blocking ratchet abutment ll strikes with its edge 11 (Fig. 2) ngninst the bent over end 60 of the locking pawl 51 and is rotated around its pivot 12 to such a degree that it slides oi! the arm 60 (Fig. 2) whereupon it falls back to its abutment position under the urge of spring 13. At the proper instant of the striking release period the release lever 33 drops from the release snail tooth. so that the release lever 63, the transmission lever 61 and finally also the locking lever 53 will be pulled back instantly by the action of the spring 14. Thcreupon the abutment engages with its oblique surface 15 against the bent over end 40 of the locking pawl 51 and forces this against the action of the spring 53 so far back that-the other end of the locking pawl engages into the locking rack plate 25 (Fig. 2). The driven sun wheel is is therefore instantly locked Without time loss. The planet wheel l1 rolls upon it and thereby turns the shaft 23 together with the portions of the quarter striking train carried by it.

The number of quarter strokes is controlled in the well known manner by the locking disc 50, since the arm 64 of the locking lever 63 of its locking position by the action of the spring 58. The driven sun wheel I8 is thusset free without time loss, while simultaneously the shaft 23 together with the planet wheel rotating on the same axis is locked by the locking disc 50.

The gear train 4, 5, 6 of the hour striking mechanism operates in an entirely similar manner. After the last 4/4 or hour stroke the hour release lever 46 is lifted by the raised cam surface of' the hour release cam 52. The free end of the lever 46 is'laterally turned as shown, and when this lever is raised, said end engages under and raises the'lever 21. At the same time the locking lever 38, 39 is raised by the trans mission lever 41 until the unilaterally blocking ratchet abutment 4D has been led past the bent over end 36 of the locking lever 33.

At the instant of the hour strike release period the hour release lever 46 drops into the low portion of the hour release disk 52 and at the same time the transmission lever 41 drops back into its starting position.

The locking lever 4| rests with its pin upon the lifted drop-in lever 21 and by this movement it has, with the oblique surface portion, as H, of its abutment pawl 40 displaced the locking lever 33 in the manner already pointed out and against the urge of spring 34 to such an extent that it looks the toothed wheel 24 of the intermediate train 4, 5, 6. The driven sun wheel 6 is thus locked without time loss, the planet wheel 5 rolls over it, and drivesthe shaft 22 with the actuator 26 and the hour hammer lifting cam 30.

The resistance of the striking hammer and its spring and other mechanism driven by the shaft 22 is sufficient to keep these parts stationary after the parts 43, 44 are unlocked before lever 33 engages with the teeth of the wheel 24.

The number of hour strokes is determined in the well known manner by the notches of the rack 28 in combination with the hour snail 29. At the last stroke, that is, when the rack 28 is in its highest position, the dropping lever 21 drops below the lower end of the rack 28. position of the drop-in lever 21 sufiices to allow the arm 4| of the locking lever 38 still to remain seated completely on the periphery of the notched disk 43. This arm 4| then is caught by the notch 44 and falls into it. Duringthis drop 7 the locking lever 39 is displaced an additional amount so that the abutment pawl 40 slides off the locking lever '36 and releases the same. This sets (the locking disk 24 and the driven sun wheel 6 is instantly set free with-out time loss. while the shaft 22, together with the planet wheel 5 rotating on the same axis, is instantly locked.

The advantages of employing a mechanism as described will be apparent, if it is considered that the synchronous clock motor, a type most generally used for the operation of clocks, is very sensitive to overloads.

It is known that suchv a motor will come to rest if the load demands a torque which is greater than the maximum load. The load carried bya synchonous clock motor is small; hence This lower the difficulties in preventing an overload when the chime striking train is clutched into the time train.

That this difficulty has been overcome in the present invention, may be explained as follows: It is a known fact that a force required to move a body out of a condition of rest, is much I greater than that, to accelerate the speed of a moving body. Therefore the stationary gears of the chime striking train when clutched into the time train require a greater forcethan if rctating. force is required to rotate the masses of gears. 6 and 24 Fig. 4. As soon as these gears are locked however, that much more force will now be available to overcome the inertia of shaft 22 and its gears, to afterward operate the chime striking train.

After this train has come to a stop again, the force released on the time train'is now switched over in part to move gears 6 and 24 out of a condition of rest.

Therefore the differential gear trains as employed, serve the purpose to always retain a certa n reserve in force, during a period of overthe inertia to be overcome when starting the chime striking train. Besides this the clutch parts are quite often connected with springs required for the release of the parts. These springs most generally cause a pressure and through this a frictional resistance on the clutch parts which would still more increase a resistance against the rotation of the chime striking train.

A special arrangement must be provided for automatically regulating the striking in case the striking means of the clock has become deranged for any' reason whatever, so that, for example, the quarter hour strike does not coincide with the time shown. This strike regulating arrangement'as in Figs. 6, 7 and 8, consists of a regulating lever 82, 83 which is associated with the transmission lever 61 at point 64, one arm of said regulating lever being adapted to rest on a pin of the hour release cam 52. The other end 82 of the lever serves as an abutment or for the release lever 68, 69, which by means of the regulating lever 82, 83 lifts the transmission lever 61. During the 4/4 strike the arm 83 is left without support on disk 52 owing to the omission of a fourth pin (similar to 80). If, however, in this position, owing to some derangement in the clockwork, one of the 1/4, 2/4, or 3/4 cams of the release cam 10 happens to lift the release lever 68, then the arm 83 will rise freely without operating the transmission lever 61. The stroke is therefore not released. It is only when, as in Fig. 8, the long 4/4 cam 8| lifts arm 69 so high that said arm 69 directly touches the transmission lever 61 and lifts it an additional distance that the transmission lever releases the strike, which will then coincide with the time indicated.

It is obvious that, by this arrangement, a

striking mechanism is provided which, when it has become deranged, will reset itself correctly within one hour.

While stationary however, a certain I It is evident from the foregoing that in the arrangement of the invention as described the drive of the striking works is derived from the continuously rotating motor without requiring any disengageable gear or clutch arrangement, or consequent loss of time needed to shift such clutch. All of the gearing of the time and strike are trains constantly in positive engagement with the driving motor. Hence it isnot possible for any train'to get out of operative phase relation with respect to the other or the motive means.

Likewise, the use of planetary gearing as a coupling means obviates the usual clutch noise incident to the operation of throwing a corresystem of simple, reliable operating levers.

In the following claims the three principal devices of the chime clock described shall be referred to as (1) time train, (2) chimes-strike control mechanism, and (3) hour striking mechanism.

The time train relates to the motor and the gearing for the rotation of the dial hands and gears 4, 4 and I6 of the two differentials 4, 5, 6 and I6, 1, II.

The control mechanism relates to the hourly and hourly chime controls connected with differentials to the time train and comprising cam and lever devices which regulate the operation of the striking mechanism.

The striking mechanism relates ,to the striking "arrangement 54. hammers, chimes and similar nism; adiflerential having an idler element, a

motive element driven by a gear of the train, and an active element connected to drive the strike mechanism when the idler element is stationary; and means to at times lock said idler element (or causing the striking, and to release" the idler element at other times to allow the strike mechanism to rest.

3. In combination, a time gear-train; a time I indicator driven by the train; a strike mechanism; a differential having an idler element, a motive element fast with a gear of the train, and an active element connected to drive the strike mechanism when the idler element is stationary; and means controlled by the time train for at times locking said idler element for causing the striking, and for releasing the idler element at other times to allow the strike mechanism to rest. I

4. In combination, a single synchronous electric motor; a time gear-train driven thereby; a time indicator driven by the train at a speed of constant ratio to the speed of the rotor; a strike mechanism of relatively small inertia; a

diflerential having an idler element, a motiveelement fast with a gear of the train, and an active element connected to drive the strike mechanism when the idler element is stationary;

and means for at times locking said idler element for causing the striking, and to release the idler element at other times to allow the strike mechanism to rest.

5. In combination, a single synchronous electric motor; a time gear-train driven thereby; a time indicator driven by the train; a strike mechanism of relatively small inertia; a difierential having an idler element, a motive element fast 10 with a gear 01 the train, and an active element connected to drive the strike mechanism when the idler element is stationary; and means for at times locking said idler element for causing the striking, and to release the idler element at other times to allow the strike mechanism to rest; the normal rotation of the whole time train, the active and idler elements, and the motor providing momentum to overcome the inertia of the strike mechanism when the latter. starts.

6. In combination, a single synchronous electric motor; a time gear-train driven thereby; a time indicator driven by the train; a strike mechanism oi! relatively small inertia; a differential havin an idler element, a motive element fast with a gear of the train, and an active element connected-to drive the strike mechanism when the idler element is stationary; means for at times locking said idler element for causing the striking, and to release the idler element at other times to allow the strike mechanism to rest; the normal rotation of the whole time train, and the active and idler elements providing momentum to overcome the inertia of the strike mechanism when the latter starts; the time indicator being at all times driven by the motor while the motor rotates at a constant ratio. to the speed of the rotor.

7. In combination, a single synchronous motor; a time gear-train driven thereby; a time indicator driven by the train; an hour strike shaft carrying a cam; a striking arm actuated by said cam; an hour-strike difierential having an idler element, a motive element fast with a gear 01 the train remote from the motor, and an inter- 5 mediate element engaged between the other two elements and mounted on the hour-strike shaft; means controlled by said train for locking said idler element for causing the hour striking, and to release the idler element at other times to allow 5 the strike shaft to rest; the normal rotation of the whole time train, and the intermediate element and idler element providing momentum to overcome the inertia of the strike shaft when the latter starts, the latter oiiering relatively small 'inertia against starting.

8. In combination, a single synchronous motor; a time gear-train driven thereby; a time indicator driven by the train; a quarter-hour strike mechanism; a quarter-hour-strike diiler- 50 ential having an idler, a motive element fast with a gear of the train near the time indicator, and an intermediate element engaged between the idler and element and connected to the quarterhour-strike mechanism; means controlled by said train for locking said idler for causing the quarter-hour striking, and to release the idler at other times to allow said mechanism to'rest; the normal rotation of the whole time train, and the intermediate element and idler providing momentum to overcome the inertia of the strike mechanism when it starts, the latter aii'ording relatively small inertia against starting.

FRITZ HECKERT. 

